drivers/usb/serial/usb_wwan.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3   USB Driver layer for GSM modems
   4
   5   Copyright (C) 2005  Matthias Urlichs <smurf@smurf.noris.de>
   6
   7   Portions copied from the Keyspan driver by Hugh Blemings <hugh@blemings.org>
   8
   9   History: see the git log.
  10
  11   Work sponsored by: Sigos GmbH, Germany <info@sigos.de>
  12
  13   This driver exists because the "normal" serial driver doesn't work too well
  14   with GSM modems. Issues:
  15   - data loss -- one single Receive URB is not nearly enough
  16   - controlling the baud rate doesn't make sense
  17 */
  18
  19 #define DRIVER_AUTHOR "Matthias Urlichs <smurf@smurf.noris.de>"
  20 #define DRIVER_DESC "USB Driver for GSM modems"
  21
  22 #include <linux/kernel.h>
  23 #include <linux/jiffies.h>
  24 #include <linux/errno.h>
  25 #include <linux/slab.h>
  26 #include <linux/tty.h>
  27 #include <linux/tty_flip.h>
  28 #include <linux/module.h>
  29 #include <linux/bitops.h>
  30 #include <linux/uaccess.h>
  31 #include <linux/usb.h>
  32 #include <linux/usb/cdc.h>
  33 #include <linux/usb/serial.h>
  34 #include <linux/serial.h>
  35 #include "usb-wwan.h"
  36
  37 /*
  38  * Generate DTR/RTS signals on the port using the SET_CONTROL_LINE_STATE request
  39  * in CDC ACM.
  40  */
  41 static int usb_wwan_send_setup(struct usb_serial_port *port)
  42 {
  43         struct usb_serial *serial = port->serial;
  44         struct usb_wwan_port_private *portdata;
  45         int val = 0;
  46         int ifnum;
  47         int res;
  48
  49         portdata = usb_get_serial_port_data(port);
  50
  51         if (portdata->dtr_state)
  52                 val |= USB_CDC_CTRL_DTR;
  53         if (portdata->rts_state)
  54                 val |= USB_CDC_CTRL_RTS;
  55
  56         ifnum = serial->interface->cur_altsetting->desc.bInterfaceNumber;
  57
  58         res = usb_autopm_get_interface(serial->interface);
  59         if (res)
  60                 return res;
  61
  62         res = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
  63                                 USB_CDC_REQ_SET_CONTROL_LINE_STATE,
  64                                 USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
  65                                 val, ifnum, NULL, 0, USB_CTRL_SET_TIMEOUT);
  66
  67         usb_autopm_put_interface(port->serial->interface);
  68
  69         return res;
  70 }
  71
  72 void usb_wwan_dtr_rts(struct usb_serial_port *port, int on)
  73 {
  74         struct usb_wwan_port_private *portdata;
  75         struct usb_wwan_intf_private *intfdata;
  76
  77         intfdata = usb_get_serial_data(port->serial);
  78
  79         if (!intfdata->use_send_setup)
  80                 return;
  81
  82         portdata = usb_get_serial_port_data(port);
  83         /* FIXME: locking */
  84         portdata->rts_state = on;
  85         portdata->dtr_state = on;
  86
  87         usb_wwan_send_setup(port);
  88 }
  89 EXPORT_SYMBOL(usb_wwan_dtr_rts);
  90
  91 int usb_wwan_tiocmget(struct tty_struct *tty)
  92 {
  93         struct usb_serial_port *port = tty->driver_data;
  94         unsigned int value;
  95         struct usb_wwan_port_private *portdata;
  96
  97         portdata = usb_get_serial_port_data(port);
  98
  99         value = ((portdata->rts_state) ? TIOCM_RTS : 0) |
 100             ((portdata->dtr_state) ? TIOCM_DTR : 0) |
 101             ((portdata->cts_state) ? TIOCM_CTS : 0) |
 102             ((portdata->dsr_state) ? TIOCM_DSR : 0) |
 103             ((portdata->dcd_state) ? TIOCM_CAR : 0) |
 104             ((portdata->ri_state) ? TIOCM_RNG : 0);
 105
 106         return value;
 107 }
 108 EXPORT_SYMBOL(usb_wwan_tiocmget);
 109
 110 int usb_wwan_tiocmset(struct tty_struct *tty,
 111                       unsigned int set, unsigned int clear)
 112 {
 113         struct usb_serial_port *port = tty->driver_data;
 114         struct usb_wwan_port_private *portdata;
 115         struct usb_wwan_intf_private *intfdata;
 116
 117         portdata = usb_get_serial_port_data(port);
 118         intfdata = usb_get_serial_data(port->serial);
 119
 120         if (!intfdata->use_send_setup)
 121                 return -EINVAL;
 122
 123         /* FIXME: what locks portdata fields ? */
 124         if (set & TIOCM_RTS)
 125                 portdata->rts_state = 1;
 126         if (set & TIOCM_DTR)
 127                 portdata->dtr_state = 1;
 128
 129         if (clear & TIOCM_RTS)
 130                 portdata->rts_state = 0;
 131         if (clear & TIOCM_DTR)
 132                 portdata->dtr_state = 0;
 133         return usb_wwan_send_setup(port);
 134 }
 135 EXPORT_SYMBOL(usb_wwan_tiocmset);
 136
 137 int usb_wwan_write(struct tty_struct *tty, struct usb_serial_port *port,
 138                    const unsigned char *buf, int count)
 139 {
 140         struct usb_wwan_port_private *portdata;
 141         struct usb_wwan_intf_private *intfdata;
 142         int i;
 143         int left, todo;
 144         struct urb *this_urb = NULL;    /* spurious */
 145         int err;
 146         unsigned long flags;
 147
 148         portdata = usb_get_serial_port_data(port);
 149         intfdata = usb_get_serial_data(port->serial);
 150
 151         dev_dbg(&port->dev, "%s: write (%d chars)\n", __func__, count);
 152
 153         left = count;
 154         for (i = 0; left > 0 && i < N_OUT_URB; i++) {
 155                 todo = left;
 156                 if (todo > OUT_BUFLEN)
 157                         todo = OUT_BUFLEN;
 158
 159                 this_urb = portdata->out_urbs[i];
 160                 if (test_and_set_bit(i, &portdata->out_busy)) {
 161                         if (time_before(jiffies,
 162                                         portdata->tx_start_time[i] + 10 * HZ))
 163                                 continue;
 164                         usb_unlink_urb(this_urb);
 165                         continue;
 166                 }
 167                 dev_dbg(&port->dev, "%s: endpoint %d buf %d\n", __func__,
 168                         usb_pipeendpoint(this_urb->pipe), i);
 169
 170                 err = usb_autopm_get_interface_async(port->serial->interface);
 171                 if (err < 0) {
 172                         clear_bit(i, &portdata->out_busy);
 173                         break;
 174                 }
 175
 176                 /* send the data */
 177                 memcpy(this_urb->transfer_buffer, buf, todo);
 178                 this_urb->transfer_buffer_length = todo;
 179
 180                 spin_lock_irqsave(&intfdata->susp_lock, flags);
 181                 if (intfdata->suspended) {
 182                         usb_anchor_urb(this_urb, &portdata->delayed);
 183                         spin_unlock_irqrestore(&intfdata->susp_lock, flags);
 184                 } else {
 185                         intfdata->in_flight++;
 186                         spin_unlock_irqrestore(&intfdata->susp_lock, flags);
 187                         err = usb_submit_urb(this_urb, GFP_ATOMIC);
 188                         if (err) {
 189                                 dev_err(&port->dev,
 190                                         "%s: submit urb %d failed: %d\n",
 191                                         __func__, i, err);
 192                                 clear_bit(i, &portdata->out_busy);
 193                                 spin_lock_irqsave(&intfdata->susp_lock, flags);
 194                                 intfdata->in_flight--;
 195                                 spin_unlock_irqrestore(&intfdata->susp_lock,
 196                                                        flags);
 197                                 usb_autopm_put_interface_async(port->serial->interface);
 198                                 break;
 199                         }
 200                 }
 201
 202                 portdata->tx_start_time[i] = jiffies;
 203                 buf += todo;
 204                 left -= todo;
 205         }
 206
 207         count -= left;
 208         dev_dbg(&port->dev, "%s: wrote (did %d)\n", __func__, count);
 209         return count;
 210 }
 211 EXPORT_SYMBOL(usb_wwan_write);
 212
 213 static void usb_wwan_indat_callback(struct urb *urb)
 214 {
 215         int err;
 216         int endpoint;
 217         struct usb_serial_port *port;
 218         struct device *dev;
 219         unsigned char *data = urb->transfer_buffer;
 220         int status = urb->status;
 221
 222         endpoint = usb_pipeendpoint(urb->pipe);
 223         port = urb->context;
 224         dev = &port->dev;
 225
 226         if (status) {
 227                 dev_dbg(dev, "%s: nonzero status: %d on endpoint %02x.\n",
 228                         __func__, status, endpoint);
 229
 230                 /* don't resubmit on fatal errors */
 231                 if (status == -ESHUTDOWN || status == -ENOENT)
 232                         return;
 233         } else {
 234                 if (urb->actual_length) {
 235                         tty_insert_flip_string(&port->port, data,
 236                                         urb->actual_length);
 237                         tty_flip_buffer_push(&port->port);
 238                 } else
 239                         dev_dbg(dev, "%s: empty read urb received\n", __func__);
 240         }
 241         /* Resubmit urb so we continue receiving */
 242         err = usb_submit_urb(urb, GFP_ATOMIC);
 243         if (err) {
 244                 if (err != -EPERM && err != -ENODEV) {
 245                         dev_err(dev, "%s: resubmit read urb failed. (%d)\n",
 246                                 __func__, err);
 247                         /* busy also in error unless we are killed */
 248                         usb_mark_last_busy(port->serial->dev);
 249                 }
 250         } else {
 251                 usb_mark_last_busy(port->serial->dev);
 252         }
 253 }
 254
 255 static void usb_wwan_outdat_callback(struct urb *urb)
 256 {
 257         struct usb_serial_port *port;
 258         struct usb_wwan_port_private *portdata;
 259         struct usb_wwan_intf_private *intfdata;
 260         unsigned long flags;
 261         int i;
 262
 263         port = urb->context;
 264         intfdata = usb_get_serial_data(port->serial);
 265
 266         usb_serial_port_softint(port);
 267         usb_autopm_put_interface_async(port->serial->interface);
 268         portdata = usb_get_serial_port_data(port);
 269         spin_lock_irqsave(&intfdata->susp_lock, flags);
 270         intfdata->in_flight--;
 271         spin_unlock_irqrestore(&intfdata->susp_lock, flags);
 272
 273         for (i = 0; i < N_OUT_URB; ++i) {
 274                 if (portdata->out_urbs[i] == urb) {
 275                         smp_mb__before_atomic();
 276                         clear_bit(i, &portdata->out_busy);
 277                         break;
 278                 }
 279         }
 280 }
 281
 282 unsigned int usb_wwan_write_room(struct tty_struct *tty)
 283 {
 284         struct usb_serial_port *port = tty->driver_data;
 285         struct usb_wwan_port_private *portdata;
 286         int i;
 287         unsigned int data_len = 0;
 288         struct urb *this_urb;
 289
 290         portdata = usb_get_serial_port_data(port);
 291
 292         for (i = 0; i < N_OUT_URB; i++) {
 293                 this_urb = portdata->out_urbs[i];
 294                 if (this_urb && !test_bit(i, &portdata->out_busy))
 295                         data_len += OUT_BUFLEN;
 296         }
 297
 298         dev_dbg(&port->dev, "%s: %u\n", __func__, data_len);
 299         return data_len;
 300 }
 301 EXPORT_SYMBOL(usb_wwan_write_room);
 302
 303 unsigned int usb_wwan_chars_in_buffer(struct tty_struct *tty)
 304 {
 305         struct usb_serial_port *port = tty->driver_data;
 306         struct usb_wwan_port_private *portdata;
 307         int i;
 308         unsigned int data_len = 0;
 309         struct urb *this_urb;
 310
 311         portdata = usb_get_serial_port_data(port);
 312
 313         for (i = 0; i < N_OUT_URB; i++) {
 314                 this_urb = portdata->out_urbs[i];
 315                 /* FIXME: This locking is insufficient as this_urb may
 316                    go unused during the test */
 317                 if (this_urb && test_bit(i, &portdata->out_busy))
 318                         data_len += this_urb->transfer_buffer_length;
 319         }
 320         dev_dbg(&port->dev, "%s: %u\n", __func__, data_len);
 321         return data_len;
 322 }
 323 EXPORT_SYMBOL(usb_wwan_chars_in_buffer);
 324
 325 int usb_wwan_open(struct tty_struct *tty, struct usb_serial_port *port)
 326 {
 327         struct usb_wwan_port_private *portdata;
 328         struct usb_wwan_intf_private *intfdata;
 329         struct usb_serial *serial = port->serial;
 330         int i, err;
 331         struct urb *urb;
 332
 333         portdata = usb_get_serial_port_data(port);
 334         intfdata = usb_get_serial_data(serial);
 335
 336         if (port->interrupt_in_urb) {
 337                 err = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
 338                 if (err) {
 339                         dev_err(&port->dev, "%s: submit int urb failed: %d\n",
 340                                 __func__, err);
 341                 }
 342         }
 343
 344         /* Start reading from the IN endpoint */
 345         for (i = 0; i < N_IN_URB; i++) {
 346                 urb = portdata->in_urbs[i];
 347                 if (!urb)
 348                         continue;
 349                 err = usb_submit_urb(urb, GFP_KERNEL);
 350                 if (err) {
 351                         dev_err(&port->dev,
 352                                 "%s: submit read urb %d failed: %d\n",
 353                                 __func__, i, err);
 354                 }
 355         }
 356
 357         spin_lock_irq(&intfdata->susp_lock);
 358         if (++intfdata->open_ports == 1)
 359                 serial->interface->needs_remote_wakeup = 1;
 360         spin_unlock_irq(&intfdata->susp_lock);
 361         /* this balances a get in the generic USB serial code */
 362         usb_autopm_put_interface(serial->interface);
 363
 364         return 0;
 365 }
 366 EXPORT_SYMBOL(usb_wwan_open);
 367
 368 static void unbusy_queued_urb(struct urb *urb,
 369                                         struct usb_wwan_port_private *portdata)
 370 {
 371         int i;
 372
 373         for (i = 0; i < N_OUT_URB; i++) {
 374                 if (urb == portdata->out_urbs[i]) {
 375                         clear_bit(i, &portdata->out_busy);
 376                         break;
 377                 }
 378         }
 379 }
 380
 381 void usb_wwan_close(struct usb_serial_port *port)
 382 {
 383         int i;
 384         struct usb_serial *serial = port->serial;
 385         struct usb_wwan_port_private *portdata;
 386         struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
 387         struct urb *urb;
 388
 389         portdata = usb_get_serial_port_data(port);
 390
 391         /*
 392          * Need to take susp_lock to make sure port is not already being
 393          * resumed, but no need to hold it due to the tty-port initialized
 394          * flag.
 395          */
 396         spin_lock_irq(&intfdata->susp_lock);
 397         if (--intfdata->open_ports == 0)
 398                 serial->interface->needs_remote_wakeup = 0;
 399         spin_unlock_irq(&intfdata->susp_lock);
 400
 401         for (;;) {
 402                 urb = usb_get_from_anchor(&portdata->delayed);
 403                 if (!urb)
 404                         break;
 405                 unbusy_queued_urb(urb, portdata);
 406                 usb_autopm_put_interface_async(serial->interface);
 407         }
 408
 409         for (i = 0; i < N_IN_URB; i++)
 410                 usb_kill_urb(portdata->in_urbs[i]);
 411         for (i = 0; i < N_OUT_URB; i++)
 412                 usb_kill_urb(portdata->out_urbs[i]);
 413         usb_kill_urb(port->interrupt_in_urb);
 414
 415         usb_autopm_get_interface_no_resume(serial->interface);
 416 }
 417 EXPORT_SYMBOL(usb_wwan_close);
 418
 419 static struct urb *usb_wwan_setup_urb(struct usb_serial_port *port,
 420                                       int endpoint,
 421                                       int dir, void *ctx, char *buf, int len,
 422                                       void (*callback) (struct urb *))
 423 {
 424         struct usb_serial *serial = port->serial;
 425         struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
 426         struct urb *urb;
 427
 428         urb = usb_alloc_urb(0, GFP_KERNEL);     /* No ISO */
 429         if (!urb)
 430                 return NULL;
 431
 432         usb_fill_bulk_urb(urb, serial->dev,
 433                           usb_sndbulkpipe(serial->dev, endpoint) | dir,
 434                           buf, len, callback, ctx);
 435
 436         if (intfdata->use_zlp && dir == USB_DIR_OUT)
 437                 urb->transfer_flags |= URB_ZERO_PACKET;
 438
 439         return urb;
 440 }
 441
 442 int usb_wwan_port_probe(struct usb_serial_port *port)
 443 {
 444         struct usb_wwan_port_private *portdata;
 445         struct urb *urb;
 446         u8 *buffer;
 447         int i;
 448
 449         if (!port->bulk_in_size || !port->bulk_out_size)
 450                 return -ENODEV;
 451
 452         portdata = kzalloc(sizeof(*portdata), GFP_KERNEL);
 453         if (!portdata)
 454                 return -ENOMEM;
 455
 456         init_usb_anchor(&portdata->delayed);
 457
 458         for (i = 0; i < N_IN_URB; i++) {
 459                 buffer = (u8 *)__get_free_page(GFP_KERNEL);
 460                 if (!buffer)
 461                         goto bail_out_error;
 462                 portdata->in_buffer[i] = buffer;
 463
 464                 urb = usb_wwan_setup_urb(port, port->bulk_in_endpointAddress,
 465                                                 USB_DIR_IN, port,
 466                                                 buffer, IN_BUFLEN,
 467                                                 usb_wwan_indat_callback);
 468                 portdata->in_urbs[i] = urb;
 469         }
 470
 471         for (i = 0; i < N_OUT_URB; i++) {
 472                 buffer = kmalloc(OUT_BUFLEN, GFP_KERNEL);
 473                 if (!buffer)
 474                         goto bail_out_error2;
 475                 portdata->out_buffer[i] = buffer;
 476
 477                 urb = usb_wwan_setup_urb(port, port->bulk_out_endpointAddress,
 478                                                 USB_DIR_OUT, port,
 479                                                 buffer, OUT_BUFLEN,
 480                                                 usb_wwan_outdat_callback);
 481                 portdata->out_urbs[i] = urb;
 482         }
 483
 484         usb_set_serial_port_data(port, portdata);
 485
 486         return 0;
 487
 488 bail_out_error2:
 489         for (i = 0; i < N_OUT_URB; i++) {
 490                 usb_free_urb(portdata->out_urbs[i]);
 491                 kfree(portdata->out_buffer[i]);
 492         }
 493 bail_out_error:
 494         for (i = 0; i < N_IN_URB; i++) {
 495                 usb_free_urb(portdata->in_urbs[i]);
 496                 free_page((unsigned long)portdata->in_buffer[i]);
 497         }
 498         kfree(portdata);
 499
 500         return -ENOMEM;
 501 }
 502 EXPORT_SYMBOL_GPL(usb_wwan_port_probe);
 503
 504 void usb_wwan_port_remove(struct usb_serial_port *port)
 505 {
 506         int i;
 507         struct usb_wwan_port_private *portdata;
 508
 509         portdata = usb_get_serial_port_data(port);
 510         usb_set_serial_port_data(port, NULL);
 511
 512         for (i = 0; i < N_IN_URB; i++) {
 513                 usb_free_urb(portdata->in_urbs[i]);
 514                 free_page((unsigned long)portdata->in_buffer[i]);
 515         }
 516         for (i = 0; i < N_OUT_URB; i++) {
 517                 usb_free_urb(portdata->out_urbs[i]);
 518                 kfree(portdata->out_buffer[i]);
 519         }
 520
 521         kfree(portdata);
 522 }
 523 EXPORT_SYMBOL(usb_wwan_port_remove);
 524
 525 #ifdef CONFIG_PM
 526 static void stop_urbs(struct usb_serial *serial)
 527 {
 528         int i, j;
 529         struct usb_serial_port *port;
 530         struct usb_wwan_port_private *portdata;
 531
 532         for (i = 0; i < serial->num_ports; ++i) {
 533                 port = serial->port[i];
 534                 portdata = usb_get_serial_port_data(port);
 535                 if (!portdata)
 536                         continue;
 537                 for (j = 0; j < N_IN_URB; j++)
 538                         usb_kill_urb(portdata->in_urbs[j]);
 539                 for (j = 0; j < N_OUT_URB; j++)
 540                         usb_kill_urb(portdata->out_urbs[j]);
 541                 usb_kill_urb(port->interrupt_in_urb);
 542         }
 543 }
 544
 545 int usb_wwan_suspend(struct usb_serial *serial, pm_message_t message)
 546 {
 547         struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
 548
 549         spin_lock_irq(&intfdata->susp_lock);
 550         if (PMSG_IS_AUTO(message)) {
 551                 if (intfdata->in_flight) {
 552                         spin_unlock_irq(&intfdata->susp_lock);
 553                         return -EBUSY;
 554                 }
 555         }
 556         intfdata->suspended = 1;
 557         spin_unlock_irq(&intfdata->susp_lock);
 558
 559         stop_urbs(serial);
 560
 561         return 0;
 562 }
 563 EXPORT_SYMBOL(usb_wwan_suspend);
 564
 565 /* Caller must hold susp_lock. */
 566 static int usb_wwan_submit_delayed_urbs(struct usb_serial_port *port)
 567 {
 568         struct usb_serial *serial = port->serial;
 569         struct usb_wwan_intf_private *data = usb_get_serial_data(serial);
 570         struct usb_wwan_port_private *portdata;
 571         struct urb *urb;
 572         int err_count = 0;
 573         int err;
 574
 575         portdata = usb_get_serial_port_data(port);
 576
 577         for (;;) {
 578                 urb = usb_get_from_anchor(&portdata->delayed);
 579                 if (!urb)
 580                         break;
 581
 582                 err = usb_submit_urb(urb, GFP_ATOMIC);
 583                 if (err) {
 584                         dev_err(&port->dev, "%s: submit urb failed: %d\n",
 585                                         __func__, err);
 586                         err_count++;
 587                         unbusy_queued_urb(urb, portdata);
 588                         usb_autopm_put_interface_async(serial->interface);
 589                         continue;
 590                 }
 591                 data->in_flight++;
 592         }
 593
 594         if (err_count)
 595                 return -EIO;
 596
 597         return 0;
 598 }
 599
 600 int usb_wwan_resume(struct usb_serial *serial)
 601 {
 602         int i, j;
 603         struct usb_serial_port *port;
 604         struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
 605         struct usb_wwan_port_private *portdata;
 606         struct urb *urb;
 607         int err;
 608         int err_count = 0;
 609
 610         spin_lock_irq(&intfdata->susp_lock);
 611         for (i = 0; i < serial->num_ports; i++) {
 612                 port = serial->port[i];
 613
 614                 if (!tty_port_initialized(&port->port))
 615                         continue;
 616
 617                 portdata = usb_get_serial_port_data(port);
 618
 619                 if (port->interrupt_in_urb) {
 620                         err = usb_submit_urb(port->interrupt_in_urb,
 621                                         GFP_ATOMIC);
 622                         if (err) {
 623                                 dev_err(&port->dev,
 624                                         "%s: submit int urb failed: %d\n",
 625                                         __func__, err);
 626                                 err_count++;
 627                         }
 628                 }
 629
 630                 err = usb_wwan_submit_delayed_urbs(port);
 631                 if (err)
 632                         err_count++;
 633
 634                 for (j = 0; j < N_IN_URB; j++) {
 635                         urb = portdata->in_urbs[j];
 636                         err = usb_submit_urb(urb, GFP_ATOMIC);
 637                         if (err < 0) {
 638                                 dev_err(&port->dev,
 639                                         "%s: submit read urb %d failed: %d\n",
 640                                         __func__, i, err);
 641                                 err_count++;
 642                         }
 643                 }
 644         }
 645         intfdata->suspended = 0;
 646         spin_unlock_irq(&intfdata->susp_lock);
 647
 648         if (err_count)
 649                 return -EIO;
 650
 651         return 0;
 652 }
 653 EXPORT_SYMBOL(usb_wwan_resume);
 654 #endif
 655
 656 MODULE_AUTHOR(DRIVER_AUTHOR);
 657 MODULE_DESCRIPTION(DRIVER_DESC);
 658 MODULE_LICENSE("GPL v2");